Renewable fuse element



June 2. 1 25- 1,540,1 19

J. B. GLOWACKI RENEWABLE FUSE ELEMENT Filed March 9, l922 EQi f MrQEE EE IEEEEE v Patented June 2, 1925 JOHN B. GLOWACKI, or cnrcaeo, framers.

RENEWABLE FUSE ELEMENT.

. Application filed much 9, 1922. Serial no. 542,253.

T0 all whom it may concern:

Be it known that I, JOHN B. GLOWACKI, a citizen of the Republic of Poland (having declared my intention of becoming a citizen of the United States), and aresident of the city of-Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Renewable Fuse Elements; and I do hereby declare that the following is a full, clear, and exact description of the same, reference being had to t e accompanying drawings, and to the numerals of reference marked thereon, which form a part of this specification.

It is an object of this invention to provide a fusible element for use in electrical fuses which shall be adapted for each of several different types of fuse cartridge.

It is a further object of this invention to provide a fusible element which shall be quick and certain in its action.

It is a further object of this invention to provide a fusible element with a scored place near each of its ends wherebythe ends may be broken off so that the central part of the element may be used alone.

It is a further object of this invention to compensate for such scored places so that the conductivity of the fuse shall not be altered thereby.

Other and further important objects of this invention will be apparent from the disclosures in the accompanying drawings and specification. p

The invention (in a preferred form) is illustrated on the drawings and hereinafter more fully described.

On the. drawings:.

Figure 1 is a sectional view of a cartridge containing the fusible element.

Figure 2 is a top plan of the fusible element.

Figure 3 is a side view thereof.

Figure 4 is an end view. v

Figure 5 is a section u 11 an enlarged scale of a portion of the fusible element near one end.

As shown on the drawings:

The cartridge 1 has the usual cylindrical container of fiber or other insulating mate- 'rial'provided with caps 2 which screw on at each end and compress the ends 4 and 5 of the fusible element 6 between the washers 7 and the closure plates 8 to which the contact blades 9 of the cartridge are secured.

. be removed The end 4 of the fusible element 6 stands at right angles to the main body of the fusible element. For convenience in assembling, the end 5 makes a small angle with the main body of the fusible element, as shown at 10. i

The fusible element, .as most clearly shown in Figure 2, is narrowed at a plurality of places 11 to make parallel sections at which the current density shall be greatest so that the element will be likely to melt first at these places. Instead of producing this narrowing by angular cuts in the edge of the strip, the corners have been rounded as indicated at 12. tions of the strip separated by the narrow portions 11 extends from one end of the fusible element to the other. But at each end of the strip, a broad portion 14 is provided, and these are wider than the broad portions just mentioned. In line with the narrow portions 11 and in the middle of each of the broad portions 14 is provided a hole 15. Beyond this hole toward the end of the strip is a scored or indented or grooved place 16. This is best shown in Figure 5 but for the sake of making the illustration clear, the depth of the groove is greatly exaggerated in this figure. Holes 17 and 18 are provided in the end portions of the stri beyond the bent parts thereof to allow 0 the escape of gases through the vent passages formed in the ends of the fuse cartridge. K

In the use of. this device with the cartridge of the form shown in Figure 1, the bent portions 4 and 5 being clasped between the metallic parts that form the end of the cartridge serve to support the strip and at the same time to afford good electrical connection between the strip and the contact blades 9. Ifthe strip is used with a form of cartridge in which the end arrangements use posts or screws, the holes 15 will accommodate such posts or screws. In many A series of broad porforms of fuse cartridge there are posts which are at right angles to the length of the strip., In the use of this fuse with such a cartridge, the bent ends of the fuse must in order that they shall not be in the way. Thegrooves 16 by weakening the fuse provide a definite point at which the bent ends may be broken off, leaving a fuse of suitable length for the type of cartridge last mentioned.

When current flows through the fuse, the grooves 16 tend to produce an increased resistance, but to counteract this, the portions 14 of the strip are made wider than the rest of the strip so that there will .be no excessive heating at the grooved places. When the current through the fuse increases, the fuse will break down first at one of the points 11. It may happen that an arc will form between the two wider portions of the fuse at various points at the moment that the narrow part 11 melts. If this should occur, the

curved character of the edges of the wider 1 parts acting on the principle of the horntype lightning arr-ester \villquickly stop such are by causing it to travel to the outer edge of the strip where the gap is longer than the arc can span. Because there are no sharp corners at this outer edge, no local discharge can occur there to maintain the arc,

I am aware that numerous details of construction may be varied through a wide range without departing from the principles of this invention, and I therefore do not purpose limiting the patent granted, otherwise 25 than necessitated by the prior art.

I claim as my invention: 1. A strip of fusible conducting material having end portions each at an angle to the plane of the 'main body of the strip, and 30 weakened portions separating said end portions from the main body of the strip. y

2. A strip of fusible material having four holes therein, a pair near each end, said strip having a weakened portion between the 3 be used to fit a differen type of cartridge.

In testimony whereof I have hereunto Sll)- scribed my name in the presence of two sub scribing witnesses.

JOHN B. GLOWACKI. Witnesses CARL'mN HILL, JAMES M. OBRIEN.

may be broken so that a portion thereof may 40 

